Many sports involve swinging a sports implement for propelling a projectile toward an opponent or across a field. These sports include golf, baseball, tennis, lacrosse, etc. A significant component of these games involves the smoothness and power of the player's swing. In the sport of baseball, it is common for a batter to practice swinging the bat with added weight, allowing the player to perceive that a bat of normal weight is light and easily swung. This effect helps the player to swing the non-weighted bat faster and harder, and theoretically to hit the ball farther.
In the sport of golf, conventional theory teaches that a smooth swing is more important than a strong swing to achieve accuracy, although strength can aid in achieving distance. Thus, both smoothness and strength are desired. Many hours of practice are devoted to improving the smoothness and control of the golfer's swing, with or without professional instruction. A major factor of improvement in any learning process is feedback, i.e. transmitting information or tactile sensations about the swing movement to the brain to reinforce the desired swing result. Prior to the present invention, there has been no known aid to help the golfer effectively feel the swing results and instantaneously obtain the important feedback for improving the swing smoothness.